Reaction jet aircraft propeller



y 13, 1952 R. J. IMBERT 2,596,406

REACTION JET AIRCRAFT PROPELLER WITH TWO AIR CIRCUITS Filed Jan. 27,1948 Iuveu'rok f, ,ad m aqmwum Patented May 13, 1952 REACTION JETAIRCRAFT PROPELLER WITH TWO AIR CIRCUITS Roger J. limbert, Paris,France, assignor to Societe Rateau (Socit Anonyme) Paris, France, acompany of France, and Ren Anxionnaz, Paris,

France, jointly Application January 27, 1948, Serial No. 4,482 In FranceFebruary 6, 1947 2 Claims. 1

Double flow reactors or reaction jet propellers have already beendescribed in United States Patent 2,396,911 corresponding to FrenchPatent 864,397 to Socit Rateau and Ren Anxionnaz, such reactorsincluding a by-pass allowing part of the air removed during compressionto pass outside the gas turbine and allowing it to be mixed at theoutput thereof with the exhaust gases in order to increase theirpropulsive emciency.

Figs. 13, 14 and 15 of this prior patent show various forms of executionof such an arrangement allowing the removal of part of the aircompressed in the low pressure stages for feeding the high pressurecompressors.

It may be of interest when it is desired to increase the dilutionoutput, that is the output of the by-passed air, to resort to a separatecompressor for said flux. This arrangement forms the object of thepresent invention that also includes means for incorporating thedilution compressor in the reactor system.

The following description and accompanying drawing will allowunderstanding how the invention may be executed, the features appearingeither in the specification or in the drawing forming obviously part ofsaid invention. In said drawing:

Fig. 1 is an axial cross-sectional view of a reaction Jet turbine thedilution flux of which is fed by aseparate axial flow compressor.

Fig. 1a shows a modification of Fig. 1.

Fig. 2 is a cross-section of Fig. 1 through line II-II thereof.

Figs. 3 and 4 are developed cross-sections through lines III-III andIV-IV, respectively, of Fig. 1.

Fig. 5 is an axial cross-sectional view of a modification wherein thedilution flux is fed by a centrifugal compressor with a helicalcentrifugal wheel.

As apparent from Fig. 1, the diluting compressor includes one or moreaxial wheels a.

Said compressor is mounted on the same shaft line as the high pressurecompressor is feeding the combustion chamber h and the driving gasturbine t and consequently rotates at the same speed. The combustionchamber is provided with fuel injectors as shown on the drawing.

The dilution air is delivered by said compressor a into an annular duct0 leading to the upstream end of the reaction nozzle 1' that is supposedto be annular in the present case and that is located immediately beyondthe last wheel b of the gas turbine t.

(Cl. fill-35.6)

The suction into the compressor is of the driving flux is operatedthrough a channel d with a circular cross-section.

As shown in Figure 1a, the suction channel it for the compressor isacting on the driving flux may be prolonged frontwardly so that bothcompressors a and k suck air in the same front chamber Z.

As the channels 0 and d should cross one another without hindering thepassage of the air and without producing any objectionable disturbancesin the fluid flow, the annularly arranged channels 0 are distributed atthe points of crossing into sections e (Fig. 2) the areas of which areproportional to the outputs to be considered while the annular system dis similarly subdivided into sections 1.

Said sections e and 1 appear clearly in Fig. 2 which is a cross-sectionthrough line IIII of Fig. 1 registering with the points at which thedifferent channels cross one another.

The channels 0 delivering the flux from the dilution compressor shouldnot lead to any disturbances inside the suction pipes d of thecompressor of the driving flux and similarly said channels itcorresponding to the suction into the latter compressor should not bedetrimental to the proper flow delivered into the channels 0 by thedilution compressor. To this purpose the different channels should beoutwardly streamlined as illustrated in Figs. 3 and 4.

Fig. 3 which is a developed cross-section through line III-III of Fig. 1shows the passage of the diluting stream between the streamlinedchannels I separating the channels 0 while Fig. 4 that is a developedcross-section through line IV-IV of Fig. 1 illustrates the passage ofthe driving flux d between two stream-lined channel systems e.

The above described arrangement is not only applicable to axialcompressors and it may be executed as well with centrifugal compressors.Fig. 5 illustrates a turbo-reactor executed along the same principlesand including a diluting compressor with a helical centrifugal wheel aland an axial compressor is for the driving flux. As apparent frominspection of said Fig. 5, the arrangement as a Whole is but littledifferent from that illustrated in Fig. 1.

The advantage of the above described arrangements consists chiefly inthe possibility of increasing the output of the dilution stream and 01'directly driving the dilution compressor a by the gas turbine, withoutspeed reducing gear, as

V sheets of light alloy metals reduce only to a small extent the gain inweight referred to.

What Iclaim is: V

1. In a double flow jet propeller comprising a jet reaction systemincluding a nozzle, heating means ahead of said nozzle, and-a mainaircom- V pressor sucking atmospheric air and delivering it towards saidheating means and said nozzle, the provision of an auxiliary aircompressor suckin atmospheric air and the suction end of which'isseparate from that of the main compressor, said auxiliary compressorbeing adapted to feed directly the reaction Jet nozzle in by-passcondition with'referen'ce to the main flux for diluting same, powermeans for driving both the main reaction jet feeding compressor and theauxiliary com pressor, channels connecting the auxiliarycompressor'delivery with the'reaction jet nozzle, and suction channelsfeeding the suction end of the main compressor and crossing thelast-mentioned channels, the channels of one series allowing thepas'sagehetween them of the flux passing through the other channels.

4 2. In a double flow jet propeller comprising a jet reaction systemincluding a nozzle, heating means ahead of said nozzle, and a main aircompressor sucking atmospheric air and delivering it towards saidheating means'and said nozzle, the

provision of an auxiliary air compressorsuckin atmospheric air and thesuction end of which is separate from that of the main compressor, saidauxiliary compressor being adapted. to feed directly the reaction jetnozzle in by-pass condition with reference to the main flux for dilutingsame, power means for driving both the main reaction jet feedingcompressor and the auxiliary compres'sor, channels connecting theauxiliary com-' pressor deliverywlth the reaction jet nozzle, and

suction channels feeding the suction end of the main-compressor andcrossing the last-mentioned ROGER J. IM B ERT.

REFERENCES CITED The following refer'ences are of record in the file ofthis patent:

UNITED STATES PATENTS Name a Anxionnaz et a1. Mar. 19, 1946' Number

